What packages do I need to install to get a bare-minimum Gnome desktop? Personally, I use Xmonad without a DE proper, but I need Gnome handy so I can do development-related testing with a regular (non-tiling) WM, panel menus, and icons. Other than that, I don't need anything gnome provides. The gnome (meta) package installs way too much stuff._________________frigidcode.com

Short answer: there isn't one. Gnome is too tightly integrated.
Corollary: gnome-light is about as stripped down as it gets. This still includes a ridicules number of packages that are "required", like cheese, etc, but it does include less than the meta.

EDIT: I don't know which version you are planning on using, but the grape vine has it that the newer versions of gnome3 will depend on systemd directly._________________First things first, but not necessarily in that order.

Last edited by The Doctor on Fri Nov 09, 2012 3:17 am; edited 1 time in total

Thanks for the help, but one more question: After installing gnome-light and logging in, gnome behaves as though it has no window manager. I.e., applications launch, but their windows are not movable and have no window bars or buttons. However, "x11-wm/metacity" is already installed on the system. Presumably there is a config setting somewhere that I need to tweak...?_________________frigidcode.com

There is a fallback mode, I suppose You are in it - but it's buggy, not properly tested etc.. even gnome team admits that.
If You don't have 3D I would recommend You use good, old, rock-solid gnome 2.32 - which is currently stable gnome version in portage tree ("arch")